中文摘要：

目的观察小鼠腭中缝在机械扩张力作用的不同阶段EphB4/ephrinB2分布和表达规律。方法选用6周龄健康雄性C57BL/6小鼠40只,随机分成对照组和实验扩张组,每组各20只。用双眼簧扩弓器施加扩张力（0.56 N）于实验加力组小鼠的腭中缝区。实验组分别于加力后1、3、7、14 d抽取5只小鼠通过石蜡切片免疫组化对EphB4/ephrinB2进行组织定位,观察表达规律并与未施力的对照组比较。结果扩张组EphB4/ephrinB2表达水平高于对照组,差异具有统计学意义。第3天实验组EphB4/ephrinB2表达水平表达最高。结论对小鼠腭中缝施加扩张力的情况下能够诱导EphB4/ephrinB2的表达增加,说明EphB4/ephrinB2在腭中缝扩张新骨改建过程中具有重要意义。

英文摘要：

Objective To observe the expression of EphB4/ephrinB2 in the maxillary palatal suture of mice during the mechanical expansion and to evaluate the effects of them on the suture remodeling during expansion.Methods 26-week-old male C57BL/6 mice were subjected to mid-palatal suture expansion by opening loops with an initial force of 0.56 N for 1,3,7 and 14 days as the expansion group.The expression of EphB4/ephrinB2 in the midpalatal suture was detected by immuno-histochemical method.Results The expression of EphB4/ephrinB2 in the expansion group was markedly higher than that of the control group.The expression of EphB4/ephrinB2 increased gradually till the 3rd day in the expansion group and then decreased with time;the highest expression was observed on the 3rd day in expansion group.Conclusions These findings demonstrated that expansion of the mid-palatal suture could promote the expression of EphB4/ephrinB2,and it might play an important role in the bone formation and bone remodeling process.